CONTINUING MEDICAL EDUCATION PROGRAM
JACS Category 1 CME Credit Featured Articles, Volume 210, February 2010 Randomized, double-blind placebo-controlled trial using lidocaine patch 5% in traumatic rib fractures Ingalls NK, Horton ZA, Bettendorf M, et al J Am Coll Surg 2010;210:205–209 Interaction of histologic subtype and histologic grade in predicting survival for soft-tissue sarcomas Canter RJ, Beal S, Borys D, et al J Am Coll Surg 2010;210:191–198 JACS CME Online provides four articles from each issue for 4 credits per month. The articles this month on JACS CME Online are: Randomized, double-blind placebo-controlled trial using lidocaine patch 5% in traumatic rib fractures. Ingalls NK, Horton ZA, Bettendorf M, et al. Interaction of histologic subtype and histologic grade in predicting survival for soft-tissue sarcomas. Canter RJ, Beal S, Borys D, et al. Prospective clinical trial of factors predicting the early development of incisional hernia after midline laparotomy. Veljkovic R, Protic M, Gluhovic A, et al. Impact of obesity on outcomes after open surgical and endovascular abdominal aortic aneurysm repair. Johnson III ON, Sidawy AN, Scanion JM, et al.
Objectives: After reading the featured articles published in this issue of the Journal of the American College of Surgeons (JACS) participants in the JACS CME program should be able to demonstrate increased understanding of the material specific to the article featured and be able to apply relevant information to clinical practice. Objectives are stated at the beginning of each featured article; the questions follow with five response choices, and a critique discussing the objective. The American College of Surgeons is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. The American College of Surgeons designates this educational activity for a maximum of 2 AMA PRA Category 1 Credits. Physicians should only claim credit commensurate with the extent of their participation in the activity.
Questions: JACS, Ph (312) 202-5316; Fax (312) 202-5027.
© 2010 by the American College of Surgeons Published by Elsevier Inc.
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ARTICLE 1 Randomized, double-blind placebo-controlled trial using lidocaine patch 5% in traumatic rib fractures
Ingalls NK, Horton ZA, Bettendorf M, et al J Am Coll Surg 2010;210:205–209
Learning Objectives: After study of this article, surgeons should be able to articulate the importance of pain management for traumatic rib fractures. They should be able to describe the novel use of the lidocaine patch 5% as an adjunct to the management of pain in these patients. Question 1
Traumatic rib fractures are: a) the second most common thoracic injury. b) rarely seen in multi-system trauma patients. c) associated with a 31% rate of pneumonia in patients 65 years and older when ⬎3 ribs are fractured. d) typically easily managed with oral pain medications. e) effectively treated with the lidocaine patch 5%.
Critique: Traumatic rib fractures are the most common thoracic injury and especially prevalent with a blunt injury mechanism (up to 40% of blunt trauma patients). They are seen both in the setting of minor trauma and in severely injured multi-system trauma patients. The pain associated with rib fractures can lead to poor pulmonary function and associated complications. This is most pronounced in patients ⬎65 years of age. When these patients have greater than three ribs fractured, their pneumonia rates can be as high as 31%. The pain associated with rib fractures can be difficult to manage and may involve oral and IV pain medications, and in some cases, an epidural catheter or regional nerve block for control. This study provides evidence that using the lidocaine patch 5% for the pain management of these patients may not add significant benefit. Question 2
Select the true statement: a) This study demonstrated a decrease in the narcotic pain medication usage among patients aged ⬎65 years who used the lidocaine patch 5% compared to the placebo patch. b) The placebo group had a statistically significantly greater number of rib fractures compared to the lidocaine patch 5% group. c) The majority of the patients in the study and placebo groups were female. d) There was no difference between patients who received the lidocaine patch 5% versus the placebo patch with
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regard to: amount of narcotic pain medication used, pain scores, pulmonary complications, or length of stay. e) The majority of patients in the study were injured as a result of penetrating trauma.
Critique: It is true that this study found no difference between patients who received the lidocaine patch 5% versus the placebo patch with regard to: amount of narcotic pain medication used, pain scores, pulmonary complications, or length of stay. Statement a is false: subgroup analysis was performed and there was no difference in the narcotic pain medication usage in the study versus placebo group when patients aged ⬎65 years were compared to their younger cohorts. Statement b is false: the study and placebo group had a similar number of ribs fractured (5.3 versus 4.9). Statement c is false: the majority of patients in the study were male (72.7% in the Lidocaine group and 76% in the placebo group). Statement e is false: most of the patients were injured as the result of a blunt mechanism, either motor vehicle accident, motorcycle accident, allterrain vehicle accident, pedestrian versus auto, or fall. ARTICLE 2 Interaction of histologic subtype and histologic grade in predicting survival for soft-tissue sarcomas
Canter RJ, Beal S, Borys D, et al J Am Coll Surg 2010;210:191–198
Learning Objectives: After reviewing this article, surgeons should be able to recognize the significant variation in survival among soft tissue sarcoma patients despite similar histologic grade. Surgeons should also recognize the importance of histologic subtype in affecting prognosis in patients with soft tissue sarcoma. Question 1
The prognosis for patients with soft tissue sarcoma: a) is determined by TNM criteria similar to those of other malignancies. b) is accurately predicted by the tumor’s histologic grade. c) approaches a 5-year survival rate of approximately 75% for patients with high grade tumors. d) is significantly influenced by the histologic type. e) has been proven to be better when radiation therapy is administered.
Critique: The American Joint Committee on Cancer (AJCC) produced a revised staging system in 2002 for soft tissue sarcoma (STS). The AJCC STS staging system is based on TNM criteria and has overall been found to correlate with survival among STS patients. However, there is significant variability within the respective AJCC stages in
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relation to prognosis, and many authors consider it to have little applicability to the care of patients with STS. Lymph node metastases occur in fewer than 5% of adult patients with STS. In contrast to epithelial malignancies, histologic grade is an established factor in the AJCC system in determing prognosis for patients with STS. However, as the current study demonstrates, histologic grade alone is imprecise for accurately predicting prognosis in patients with STS. Overall, the 5-year survival among patients with high grade tumors was 61.7%, but this varied from 41.1% to 75.7% depending on histologic subtype. Accumulating evidence suggests that the 50 to 100 different subtypes of STS exhibit unique patterns of spread, recurrence, and prognosis. Mortality rates vary by 3- to 10-fold within categories of histologic grade depending on histologic type. Radiation therapy is important in the adjuvant treatment of patients with soft tissue sarcoma. Multiple studies have demonstrated its efficacy in lowering local recurrence rates, particularly in the era of limb-sparing surgery. However, no study has demonstrated a significant difference in survival when surgical resection plus radiation is compared to surgical resection alone. Question 2
Patients with soft tissue sarcoma: a) present with primary tumors greater than 10 centimeters in size in the majority of cases. b) typically undergo amputation to successfully treat tumors on the extremities. c) require adjuvant radiotherapy following surgical resection. d) tend to have similar baseline clinical and tumor characteristics. e) benefit from precise determination of histologic subtype since knowledge of unique biological behavior among STS subtypes is important for optimal multimodality care.
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Critique: Among patients with STS, primary tumor size is relatively evenly distributed among size categories (ⱕ 5 cm, 5 to 10 cm, and ⬎ 10 cm). Median tumor size is generally 7–8 cm. In most specialized centers, amputation rates for primary tumors are currently 3–5%. Amputation is generally limited to cases of very advanced tumors or distal tumors in which it does not appear possible to perform a complete resection without compromising limb function. Adjuvant radiotherapy is a proven method for limiting local recurrence. However, for patients with lesions smaller than 5 cm, adjuvant radiation therapy adds little to complete surgical excision, except in cases of recurrent sarcoma. Similarly, for atypical lipomatous tumors/ well-differentiated liposarcoma of the extremity, the local recurrence rate following surgical resection is sufficiently low that postoperative external beam radiotherapy is rarely necessary even in cases with microscopically positive margins. All other patients, particularly if excised with margins less than 1 cm, should be considered for adjuvant radiotherapy. STS comprise a heterogenous group of rare diseases. Clinical and tumor characteristics can vary widely based on factors such as histological type, histological grade, tumor size, and tumor location. Synovial sarcoma, malignant peripheral nerve sheath tumor, and leiomyosarcoma are more common in younger patients while malignant fibrous histiocytoma/pleomorphic sarcoma and liposarcoma are more common in older patients. Careful and accurate determination of histologic subtype is essential for precise patient prognostication and provides important information beyond that of histologic grade. For example, Ewing’s sarcoma/primitive neuroectodermal tumor has an approximate 90% mortality rate without chemotherapy, but with multimodality therapy, the outcome is substantially improved. It is hoped that the advent of improved molecular techniques will lead to the development of targeted therapies specific to individual STS histological types.